es6中的Set对象对数据进行去重、并集、交集、差集
let a=[1,3,2,4,5,12,7,26,19,6,2,8,12,9];
let b=[2,5,48,23,26,8,12];
1,数组去重:
let setA=new Set(a);
let c=Array.from(setA)
2,数组并集
let setB=new Set(b);
let d=[...new Set(...setA,...setB)]
3, 数组交集
let e=[...new Set(setA)].filter(item=> setB.has(item))
4,数组差集
let f=[...new Set(setA)].filter(item=>!setB.has(item))